it's been a while since i used proton basic but a few things to check are you tx & rx wires are the right way round, also serial polarity because if your using a max 232 between uC ans PC the signal will be inverted, you can set that in basic, I dont think the f88 has hardware uart so forget HSER, stick with serin serout, make sure your xtal frequency is correctly define or serial wont have a chance, for now forget arduino part of it and just get the pic to talk to pc